import java.util.Scanner;

public class MaxCommon {
    //求两个正整数的最大公约数

    //辗转相除法
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = a % b;
        while(c != 0){
            a = b;
            b = c;
            c = a % b;
        }
        System.out.println(b);
    }
}
